[NEW DELHI] As urban air quality over India is seen to be deteriorating rapidly environment experts are demanding tighter measures to protect the health of citizens, such as by reining in the number of vehicles on the roads.

A recent study by The Energy and Resources Institute (TERI), New Delhi, laid blame on the rising number of vehicles on the capital city’s roads. “Vehicle emissions contribute to PM 2.5 and NOx," the report said.

"Under current trends in growth of vehicles and with current fuel and emission standards, the transport sector emissions of PM 2.5 will increase by a factor of three and emissions of NOx by a factor of five,” said the report by TERI, now gearing up to organise the annual Delhi Sustainable Development Summit, early February.

PM 2.5 describes particles in the air, smaller than two and one half microns that can affect lung function and known to worsen medical conditions such as asthma and heart disease. NOx refers to oxides of nitrogen that also aggravate heart and respiratory conditions.

According to Anumita Roy Chowdhury, executive director of research and advocacy at CSE, vehicles are not the only sources of PM 2.5 besides vehicles, but 70—80 per cent of NOx comes from vehicular emissions.

Sarath K. Guttikunda, adjunct associate professor at the Centre for Climate Studies, Indian Institute of Technology, Bombay, says that sectors other than transport such as brick kilns and power plants are being ignored by policy makers and advocacy groups as major sources of urban air pollution.

“You see cars and buses belching smoke every day and you assume that is what is causing it — we forget that construction is a major source of dust pollution. Or brick kilns that burn everything imaginable,” says Guttikunda who published a paper in Atmospheric Environment in October showing that road transport is only one of several major contributors to air pollution in Indian cities.

An air quality index launched by the government in October uses colour coding to track eight key pollutants and indicate the levels at which they affect human health, but there is no provision for follow up action even when the highest levels are reached.

“The index at present informs people; it is a government health advisory,” says Roy Choudhury. “The moment you hit the red zone, you need emergency measures. Beijing, for instance, closes primary schools and takes 80 per cent of government vehicles off the road.”

A report released by WHO in May 2014 placed New Delhi at the top of a list of 1,600 cities from 91 countries with hazardous air quality. Of the 67 risk factors considered in the report, outdoor air pollution ranked fifth in mortality and seventh in health burden in India — contributing in 2010 to over 627,000 deaths and 17.7 million healthy years of life lost.